Week 7: Fungi and Parasites

Question 1

When was the The Rockefeller Sanitary Commission for the Eradication of
Hookworm Disease?

Answer 1

1909

Question 2

What organisms are key contributors to human infections?

Answer 2

Eukaryotic organisms such as fungi, protozoa, and parasites.

Question 3

How do Eukaryotic organisms differ from bacteria and viruses?

Answer 3

Their structure, their life cycles, and their interactions with human hosts.

Ex. Cells contain a membrane-bound nucleus, and organisms can be unicellular or multicellular

Question 4

What are Fungi?

Answer 4

A diverse group of organisms that can range from unicellular yeasts to multicellular filamentous moulds and even large mushrooms

Question 5

What is Candida albicans?

Answer 5

A naturally occurring fungus (yeast) that is typically found in small amounts on the human body

Question 6

What sort of infections are caused by an overgrowth of Candida albicans?

Answer 6

Thrush
Vaginal yeast infection
Invasive candidiasis

Question 7

What is Aspergillus?

Answer 7

Filamentous fungi found in soil and in decaying/moist vegetation

Question 8

How many species of Aspergillus exist?

Answer 8

~180 species

Question 9

Which Aspergillus species most commonly causes infections?

Answer 9

Aspergillus fumigatus

Question 10

How do species of Aspergillus infect a person?

Answer 10

Through the lungs, sinuses, or burn wounds

Question 11

Do most people who come into contact with Aspergillus spores get sick?

Answer 11

No

Question 12

What is Coccidioidomycosis?

Answer 12

A fungal illness known as Valley Fever

Question 13

How far can Coccidioidomycosis spores travel?

Answer 13

> 500 km in the wind

Question 14

Who can Coccidioidomycosis infect?

Answer 14

Mostly humans, but also animals

Question 15

What are the symptoms of a Coccidioidomycosis infection?

Answer 15

Similar to a respiratory infection (cough, fever, chest pain, fatigue).

Question 16

What are Cryptococcus?

Answer 16

Cryptococcus species are
environmental fungi primarily found in tree hollows and avian excreta, with C. neoformans being
globally distributed and C. gattii more prevalent in tropical and subtropical regions.

Question 17

How does an infection of Crytococcus occur?

Answer 17

Infection typically occurs through the inhalation of fungal spores or desiccated cells (dried out) from the environment, leading to pulmonary infections that can disseminate to the central nervous system (CNS), especially in immunocompromised individuals.

Question 18

What is Pneumocystis jirovecii?

Answer 18

An opportunistic disease caused by the unicellular fungus

Question 19

What is a parasite?

Answer 19

A parasite is an organism that lives on or in a host and gets its food from that host, though this eukaryotic species is different from bacteria, viruses, and fungi

Question 20

What are some types of parasites that impact human health?

Answer 20

1. Protozoa
2. Helminths such as nematodes (roundworms)
   trematodes (flukes)
   cestodes (tapeworms)
3. Ectoparasites (bed bugs)
4. Ticks

Question 21

What are Protozoa?

Answer 21

Single-celled organisms that can multiply to cause
serious infection

Question 22

What are the 2 routes of transmission for Protozoa?

Answer 22

Fecel-oral
Vectors (mosquitoes)

Question 23

What are some common Protozoan infections?

Answer 23

Cytosporidiosis
Giardiasis
Toxoplasmosis
Trichomoniasis

Question 24

What is Giardasis?

Answer 24

An enteric disease
that is caused by the parasite Giardia

Question 25

What is the most common transmission route for Giardasis?

Answer 25

Humans typically become infected when they come into contact with the feces of an infected animal – typically in water, though can be spread from person to person

Question 26

What is Cryptosporidiosis?

Answer 26

An enteric infection and is caused by the parasite Cryptosporidium

Question 27

What is the mode of transmission for Cryptosporidium?

Answer 27

Water-related infection

Question 28

What is Toxoplasmosis?

Answer 28

Caused by Toxoplasma gondii, a common human infection with an estimated half the global population being infected with the majority of cases being asymptomatic. Can be found in animals, birds, and soil

Question 29

What are Helminths?

Answer 29

Helminths are among the largest parasites affecting humans, animals, and plants, with some species like the fish tapeworm (Dibothriocephalus) growing over 20 meters long.

Question 30

What are the 4 groups Helminths can be divided into?

Answer 30

Nematoda Platyhelminths Pentastomida Acanthocelphala

Question 31

What is different about the life cycle of Helminths?

Answer 31

Unlike bacteria and viruses, helminths have complex life cycles that can involve direct transmission, vector mediation, or ingestion by the host, however they do not replicate within the human host.

Question 32

What is unique about Hemlinths reproduction?

Answer 32

They exhibit a range of reproductive strategies, including separate sexes and hermaphroditism, with some species even showing parthenogenetic reproduction, where females reproduce without males

Question 33

What are Roundworms (nematodes)?

Answer 33

They are among the most common parasites in humans, particularly in areas with poor sanitation

Question 34

What is the most common type of Nematode?

Answer 34

Enteric

Question 35

What sort of relationship do Nematodes have with their host?

Answer 35

Most enteric nematodes have a balanced relationship with their human hosts, causing minimal disease with light infections. However, heavy worm loads can lead to significant health issues, including intestinal inflammation, blockage, and migration-related damage.

Question 36

What is Ascariasis?

Answer 36

It is caused by the parasitic roundworm Ascaris lumbricoides, the most common worm parasite worldwide

Question 37

What sort of populations are at risk of Ascariasis?

Answer 37

Populations at risk include those with poor food sanitation by consuming eggs found in contaminated soil

Question 38

What did Dr. Giovanni Battista Grassi discover?

Answer 38

The transmission and life cycle of Ascaris

Question 39

What are the two groups of Flatworms (Platyhelminthes)?

Answer 39

Tapeworms and flukes

Question 40

What are Ectoparasites?

Answer 40

Parasites that live on the outside of the host

Question 41

What are some examples of Ectoparasites?

Answer 41

Bed bugs Lice Scabies

Question 42

What are Bed Bugs?

Answer 42

They are small, flat, and wingless, blood-feeding insects that have affected humans for thousands of years.

Question 43

What are Lice?

Answer 43

Tiny, wingless parasites that live on the body, commonly found on the head, body, or pubic area.

Question 44

What are the two types of Ticks?

Answer 44

Hard ticks (Ixodidae) Soft ticks (Argasidae)

Question 45

What are Hard ticks (Ixodidae)?

Answer 45

Characterized by a hard shield on their back, these ticks are the most commonly encountered and include species like the Black-legged Tick and American Dog Tick.

Question 46

What are Soft Ticks (Argasidae)?

Answer 46

These ticks have a more leathery appearance and are typically found in more specific habitats, such as bird nests or bat caves.

Question 47

What is the Erythma Migrans Rash?

Answer 47

"Bullseye" rash that some people with Lyme disease will have